Electrical utility service providers, or simply utilities, monitor energy usage by customers through electrical utility meters. Electrical utility meters track the amount of energy consumed, typically measured in kilowatt-hours ("kwh"), at each customer's facility. Utilities use the consumption information primarily for billing, but also for resource allocation and other purposes.
Utilities generate polyphase electrical power, and typically three phase power. Polyphase electrical power is alternating current electrical power that is supplied on a plurality of power supply lines. The voltage waveform on each of the power supply lines has a unique phase angle. While only a single phase of the polyphase electrical power is typically provided for single family dwellings, true polyphase electrical power is generally provided to larger facilities such as commercial and industrial structures.
Historically, electrical utility meters utilized an inductive spinning disk to measure energy consumption. In such meters, the rate at which the spinning disk rotates varies proportionately to the amount of electrical power being consumed. The spinning disk drives mechanical counters, which, in turn, provide the accumulated energy usage information.
A recent development in electrical utility meters are electronic meters. Electronic meters replace the older inductive spinning disk meter design. Electronic meters have several advantages, including the advantage of providing features beyond straight-forward power consumption metering. Electronic meters, may, for example, track energy demand, power factor, and per phase power measurements. In addition, electronic meters may alter the method by which they calculate energy consumption in order to accommodate several building wiring and power configurations, thereby increasing the versatility of the meters.
Electronic meters are also capable of fairly sophisticated diagnostics. For example, U.S. Pat. No. 5,469,049 to Briese et al. teaches a diagnostic toolbox that is built into the meter. The diagnostic toolbox in the Briese et al. device measures per phase voltage and current magnitude and phase angles, and then compares the measured values with expected values to determine whether a wiring error is present. A wiring error is an error either in the meter itself or in the interface between the meter and the electrical system to which it is connected. Wiring errors typically cause a meter to make substantially inaccurate power measurements. As a result, wiring errors can cause loss of substantial revenue to utilities because the meter does not accurately record the actual energy amount that is consumed.
A drawback to the meter disclosed in the Briese et al. patent is that it displays identified errors, but requires servicing to correct the errors. Thus, while an error may be detected and displayed, the utility will continue to lose revenue until a service person can be dispatched to correct the error. Another drawback to the Briese et al. meter is that the meter must be preconfigured for the wiring configuration and voltage level, or service type, to which it is connected. The preconfiguration requirement is undesirable. For example, preconfiguring the meter during its manufacture introduces unwanted complexity into the inventory and delivery systems. Likewise, requiring that a technician provide such input to the meter during installation undesirably increases the complexity associated with installing the meters.